I agree that the iOS file system extraction is in fact just logical acqusition. (4 and later)
I was using term 'physical' in content of iOS just because I was using Elcomsoft iOS forensic toolkit and they called it 'physical' (creating dmg image for 4s,5,5c and later TAR archive).
Physical acquisition is the binary image of a chip.
Filesystem acquisition (encrypted or not) is a logical acquisition.
2) Is it possible to ask facebook/instagram (by simple request or subpoena) to recover for us the activity usage and the search history deleted ?
Why don`t you try with data extraction from cloud?
We tried the data extraction from Cloud for Facebook with Axiom, but there was not the option of the search history in it. Is there another software like oxygen that has the option of search history with the data cloud extraction ?
Also the whatsapp cloud extraction didn t work with axiom, we couldn t connect the account to it.